Development of high strength complex boride base hard materials produced by reaction boronizing sintering

摘要

Borides are promising candidates for wear resistant materials. But poor sinterability and extreme brittleness of borides retarded the fabrication of bulk materials. This paper gives criteria for the development of boride base cermets. Reactionboronizing sintering developed by us is a novel strategy to form a ternary boride coexisting with a binder metal during sintering associated with liquid phase formation. This new sintering technique has successfully brought development of three ternaryboride base cermets such as Mo{sub}2FeB{sub}2, Mo{sub}2NiB{sub}2 and WCoB base ones. This paper describes the sintering behavior, mechanical properties, microstructure and phase formation related with the alloying elements on Mo{sub}2NiB{sub}2 boride base cermets. This paper also illustrates Reitveld analysis results of the complex boride structure in the cermets.